Publications by authors named "Shuhei Satake"

Porphyrin derivatives with hydroxyphenyl or dihydroxyphenyl moieties in the meso-position were able to dissolve in water by complexation with two trimethyl-β-cyclodextrins (TMe-β-CDxs) without further chemical modification of porphyrins or addition of dimethyl sulfoxide as a co-solvent. TMe-β-CDx-complexed tetra(hydroxyphenyl)porphyrins (THPPs) with phenols in meso-positions have a much higher photodynamic activity than TMe-β-CDx-complexed tetrakis(dihydroxyphenyl)porphyrins (TDHPPs) with dihydroxyphenyl in the meso-position. The main reason for the different photoactivity is due to the intracellular uptakes of these complexes.

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5,15-Diazaporphyrins, which have a large absorption at wavelengths over 600 nm, were dissolved in water by complex formation with β-(1,3-1,6)-d-glucans. Aqueous solutions of these complexes were relatively stable compared with their trimethyl-β-cyclodextrin-complexed analogues. β-Glucan-complexed diazaporphyrins showed quenched fluorescence and had low singlet-oxygen-generation abilities owing to random self-aggregation.

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Water-soluble inclusion complexes of 5,15-diazaporphyrin derivatives in the cavities of two trimethyl-β-cyclodextrins (TMe-β-CDxs) were synthesised. In the 2 : 1 complexes, two aryl groups of the diazaporphyrins protruded from the upper rims of two TMe-β-CDxs. The complexes displayed high photodynamic activity under photoirradiation at wavelengths longer than 620 nm.

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The weak absorbance of pristine C , C , and fullerene derivatives at wavelengths over 600 nm hampers the use of these molecules as photosensitizers (PSs) for photodynamic therapy (PDT). The coexistence of light-harvesting antenna molecules with a fullerene derivative in lipid membrane bilayers solved this issue. By controlling the location of the C derivative in the lipid membrane, the liposomal dyad system for PDT improved the photodynamic activity via an efficient photoenergy transfer from antenna molecules to the fullerene derivative.

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Water-soluble cyclodextrin (CyD) complexed with porphyrin derivatives with different substituents in the -positions showed different photodynamic activities toward cancer cells under illumination at wavelengths over 600 nm, the most suitable wavelengths for photodynamic therapy (PDT). In particular, aniline- and phenol-substituted derivatives had high photodynamic activity because of the efficient intracellular uptake of the complexes by tumor cells. These complexes showed greater photodynamic activity than photofrin, currently the main drug in clinical use as a photosensitizer.

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